钌多吡啶配合物的合成及插入配体的位阻效应对键合DNA的影响

合成了2,3-二甲基-1,4,8,9-四氮三联苯(dmtatp)和2,3-二苯基-1,4,8,9-四氮三联苯(dptatp)两种新配体及它们与2,2′-联吡啶和钌(Ⅱ)的混配物[Ru(bpy)₂dmtatp]²⁺(1)和[Ru(bpy)₂dptatp]²⁺(2),用电子吸收光谱、稳态荧光、粘度测定和圆二色谱研究了配合物与小牛胸腺DNA的相互作用。结合我们以前对配合物[Ru(bpy)₂tatp]²⁺(3)(tatp为1,4,8,9-四氮三联苯)与小牛胸腺DNA的作用研究,得出配合物与DNA的键合强度顺序为:[Ru(bpy)₂tatp]²⁺>[Ru(bpy)₂dptatp]²⁺>[Ru(bpy)₂dmtatp]²⁺,这与插入配体的位阻效应的减少趋势相一致。同时,还测定了配合物与DNA的键合常数。     

Photophysics of ruthenium(II) complexes with 2-(2′-pyridyl) pyrimidine and 2,2′-bipyridine ligands in fluid solution

The photophysics of three complexes of the form Ru(bpy)₃₋(pypm)²⁺ (where bpy2,2′-bipyridine, pypm 2-(2′-pyridyl)pyrimidine and P=1, 2 or 3) was examined in H₂O, propylene carbonate, CH₃CN and 4:1 (v/v) C₂H₅OH---CH₃OH; comparison was made with the well-known photophysical behavior of Ru(bpy)₃²⁺. The lifetimes of the luminescent metal-to-ligand charge transfer (MLCT) excited states were determined as a function of temperature (between −103 and 90 °C, depending on the solvent), from which were extracted the rate constants for radiative and non-radiative decay and ΔE, the energy gap between the MLCT and metal-centered (MC) excited states. The results indicate that ^*Ru(bpy)₂(pypm)²⁺ decays via a higher lying MLCT state, whereas ^*Ru(pypm)₃²⁺ and ^*Ru(pypm)₂(bpy)²⁺ decay predominantly via the MC state.     

Tris-chelate complexes with chiral ligands: In search of diastereoisomeric selectivity with remote stereogenic centres

The chiral ligands, 4,4′-bis{(1S,2R,4S)-(−)-bornyloxy}-2,2′-bipyridine, (1S,2R,4S)-1, and 4,4′-bis{(1R,2S,4R)-(+)-bornyloxy}-2,2′-bipyridine, (1R,2S,4R)-1, have been prepared and characterized by spectroscopic techniques and, for (1S,2R,4S)-1, by single crystal X-ray diffraction. Despite the use of enantiomerically pure ligands, the formation of the complexes [Fe((1S,2R,4S)-1)₃]²⁺, [Ru((1S,2R,4S)-1)₃]²⁺, [Ru((1S,2R,4S)-1)(bpy)₂]²⁺ and [Ru((1R,2S,4R)-1)(bpy)₂]²⁺ proceeds without preference for either the Δ or Λ-diastereoisomers.     

Ruthenium(II)-cored supramolecular organic framework-mediated recyclable visible light photoreduction of azides to amines and cascade formation of lactams

Porous[Ru(bpy)₃]²⁺-cored supramolecular metal organic framework can efficiently catalyze visible light photoreduction of various azides to afford amines and, through cascade reactions, lactams.     

Fabrication and Photoelectrochemical Properties of [Ru(bpy)2dppz]2+ on ITO Electrode Associated with the Oxidation of Guanine

<正>Electrochemical assembly of[Ru(bpy)_2dppz]~(2+){bpy=2,2'-bipyridine,dppz=dipyrido[3,2-a:2',3'-c]phenazine} on an ITO electrode in the presence of guanine and photoelectrochemical properties of the assembled layer were investigated.It has been found that[Ru(bpy)_2dppz]~(3+/2+) can be assembled onto the ITO electrode by the method of repetitive voltammetric sweeping,and the assembly is enhanced by guanine.The peak currents of prewaves increase linearly up to a guanine concentration of 0.25 mmol/L.More importantly,upon illumination with 470 nm light source and at an applied potential of 0.2 V,cathodic current for the fabricated layer on the ITO electrode indicate a linear enhancement with the rise of guanine concentration.Meanwhile,[Ru(bpy)_2dppz]~(2+) can be served as an excellent mediator to prompt the oxidation of guanine,and the mediated peak current increases linearly with added guanine concentration from 0.01 to 0.25 mmol/L.In addition,the assembly mechanism of[Ru(bpy)_2dppz]~(2+) on the ITO electrode associated with the oxidation of guanine and the assistance of light irradiation were discussed.     

Rates of virtually self-exchange energy transfer processes of ruthenium(II) polypyridine complexes

The rate constants of electronic energy transfer from the lowest excited state of Ru(bpy)₂(L)²⁺ or Ru(bpy)(L)₂²⁺ 10 Ru(L)₃²⁺ (b     

取代基对咪唑[4,5-f]-1,10-邻菲罗啉Ru(Ⅱ)配合物的温敏性能影响

合成了3种具有不同取代基的咪唑[4, 5-f]-1,10-邻菲罗啉配体L¹~L³及其Ru(Ⅱ)配合物[Ru(L¹)₃]、[Ru(L²)₃]和[Ru(L³)₃],并进行了表征。这些Ru(Ⅱ)配合物在溶液中具有π→π^*跃迁吸收峰和金属到配体的电荷转移跃迁(MLCT)吸收峰,其发光峰位约为590 nm左右。将Ru(Ⅱ)配合物掺杂到聚甲基丙烯酸甲酯(PMMA)中得到相应的温敏漆。Ru(Ⅱ)配合物在PMMA膜中的吸收峰精细结构消失,且在长波方向663 nm附近有新的发射峰,表明Ru(Ⅱ)配合物在PMMA膜中有聚集。温度升高后,Ru(Ⅱ)配合物在PMMA膜中的发射峰强度逐渐减弱。分别计算了在30~60 ℃和60~90 ℃区间内非辐射活化能E_nr和温度灵敏度S_T。结果表明,具有苯基取代的咪唑[4, 5-f]-1,10-邻菲罗啉配体的[Ru(L¹)₃]配合物,比咪唑[4, 5-f]-1,10-邻菲罗啉Ru(Ⅱ)配合物[Ru(L²)₃]及烷基取代基的咪唑[4, 5-f]-1,10-邻菲罗啉Ru(Ⅱ)配合物[Ru(L³)₃]具有更高的温度灵敏度。     

Stabilization and electron spin resonance characterization of Ru(bpy)3 and Ru(bpy)3 by radiolysis of Ru(bpy)3 adsorbed on silica gel

Ru(bpy)₃³⁺, which is important in artificial photosynthetic systems due to its high reduction potential, is stabilized together with its counter anion, Ru(bpy)₃⁺, by radiolysis of Ru(bpy)₃²⁺ adsorbed on silica gel at 77 K. Both species are characterized by electron spin resonance.     

New rhodium---ruthenium heterobimetallic complexes with bridging bi- or tri-dentate phosphine ligands

The mononuclear chelated complex [RuCl(Cp)(η²-dppa)] has been synthesised and reacted with [Rh₂Cl₂(CO)₄] to form the heterobimetallic complex [(Cp)Ru(μ-CO)₂{(μ-Ph₂PN(H)PPh₂}RhCl₂]. Complexes of [RuCl(Cp){(PPh₂)₂CHCH₂PPh₂}] have been reacted with [Rh₂Cl₂(CO)₄] or [RhCl(CO)₂(p-toluidene)]. Characterisation of these new ruthenium complexes was carried out using ³¹P-NMR, FAB mass spectroscopy, elemental analysis and IR spectrophotometry.     

Preparation and characterization of [Re(bpy)(CO) 3L][SbF6] (L = phosphine, phosphite)

A series of rhenium complexes [fac-Re(bpy)(CO)₃L][SbF₆] (bpy = 2,2′-bipyridine, L = P(ⁿBu)₃, PEt₃, PPh₃, P(OMe)Ph₂, P(OⁱPr)₃, P(OEt)₃, P(OMe)₃, P(OPh)₃) has been prepared and characterized by the IR, UV-vis, ¹H NMR, ³¹P NMR, X-ray photoelectron spectroscopy and electrochemical techniques. Variations in the electronic properties, i.e. CO stretching, metal-to-ligand charge transfer transition, and ³¹P NMR chemical shifts were interpreted on the basis of the electron-acceptor strength of L. However, the redox potential corresponding to [Re(bpy)(CO)₃L]⁺/[Re(bpy⁻)(CO)₃L]showed ‘V-character type’ changes after the increase in the electron-acceptor strength of L. Variation of the P(2p) binding energy of the phosphorus atom indicated that the electronic structure of the coordinated phosphorus atom was strongly influenced by the electronic properties of the directly attached substituents.     

Equilibrium reactions network for the cis- or trans-bis(pyrazine)tetraammineruthenium(II/III) and ruthenium(II/III)-EDTA complexes

The electrochemical and spectroelectrochemical behavior of the binuclear and trinuclear complexes generated from the association of cis- or trans-[Ru(NH₃)₄(pz)₂]^3+/2+ (where pz represents pyrazine) and [RuEDTA(H₂O)]^2−/− complexes has been investigated in aqueous solution. Based on two sets of spectrophotometrically determined equilibrium constants and on the formal redox potentials, the complex network of equilibrium reactions involving mixed valence species has been elucidated.     

Synthesis and Fluorescence of a New Active Material for Electrochemiluminescent Sensor:Ru(phen)2[phen-NHCO(CH2)4Br](PF6)2

Recently, much attention has been paid to Ru(II) complexes because of their excellent properties of photochemistry, phtophysis. Bis(2,2'-bipyridine)[4-methyl-4'-(6-bromohexyl)-2,2'-bipyridine] ruthenium(II) perchlorate has been used as an active material for electrochemiluminescent (ECL) sensor for selective detection of oxalic acid.It is known that ECL efficiency of Ru(phen)₃²⁺ is much higher than that of Ru(bpy)₃²⁺. In order to make out more efficient ECL sensor, we have designed and synthesized a new Ru(II) complex, Ru(phen)₂[phen-NHCO(CH₂)₄Br](PF₆)₂.     

Hydrogen peroxide photoproduction by the semicarbazide—tris(2,2′-bipyridine)ruthenium(II)—oxygen system

A light-driven system consisting of tris(2,2′-bipyridine)ruthenium(II) (Ru(bpy)₃²⁺) as the photosensitizer, semicarbazide as the electron donor and molecular oxygen as the electron acceptor has been employed for hydrogen peroxide production. The efficiency of this photosystem markedly depends on pH: while the peroxide yield is almost negligible at acid, neutral or slightly alkaline pH, it reaches significant values at high hydroxide concentrations, the initial rate of H₂O₂ formation drastically increasing from pH 12 to pH 14. In 1 M NaOH solutions containing Ru(bpy)₃²⁺ and semicarbazide at optimum concentrations, the number of catalytic cycles (or turnover number) undergone by the ruthenium complex over the complete course of the photochemical reaction is as high as 1.1 × 10⁴.

Spectrofluorometric and laser flash photolysis techniques were used to study the primary photochemical reactions involving the excited state of the ruthenium complex as well as the photochemically generated species Ru(bpy)₃³⁺ and Ru(bpy)₃⁺. It is proposed that at pH 14 a sequence of reactions leading to O₂ photoreduction by electrons from semicarbazide takes place, with the concomitant formation of H₂O₂; the excited state of Ru(bpy)₃²⁺ appears to react via oxidative quenching by oxygen rather than via reductive quenching by semicarbazide. At neutral pH, in contrast, there is no H₂O₂ formation owing to the fact that semicarbazide is unable to reduce (Ru(bpy)₃³⁺ to Ru(bpy)₃²⁺, although the photoexcited ruthenium complex is quenched equally by oxygen.     

Synthesis, structure and nuclease activity of copper complexes of disubstituted 2,2′-bipyridine ligands bearing ammonium groups

A series of Cu(II) complexes of disubstituted 2,2′-bipyridine bearing ammonium groups [Cu(L¹⁻⁴)₂Br]⁵⁺ (1–4, L¹ = [5,5′-(Me₂NHCH₂)₂-bpy]²⁺, L² = [5,5′-(Me₃NCH₂)₂-bpy]²⁺, L³ = [4,4′-(Me₂NHCH₂)₂-bpy]²⁺, L⁴ = [4,4′-(Me₃NCH₂)₂-bpy]²⁺ and bpy = 2,2′-bipyridyl) were synthesized, of which complexes 1 and 4 were structurally characterized. Both coordination configurations of Cu(II) ions can be described as distorted trigonal bipyramid. The interaction between all complexes and CT-DNA was evaluated by thermal-denaturation experiments and CD spectroscopy. Results show that the complexes interact with CT-DNA via outside electrostatic interactions and their binding ability follows the order: 1 > 2 > 3 > 4. In the absence of any reducing agents, the cleavage of plasmid pBR322 DNA by these complexes was investigated and the hydrolysis kinetics of DNA was studied in Tris buffer (pH 7.5) at 37 °C. Obtained pseudo-Michaelis–Menten kinetic parameters: 15.0, 13.6, 2.01 and 1.69 h⁻¹ for 1, 2, 3 and 4, respectively, indicate that complexes 1 and 2 exhibit very high DNA cleavage activities. According to their crystal data, the high nuclease activity may be attributed to the strong interaction of the metal moiety and two ammonium groups with phosphate groups of DNA.     

Reaction of [(C6H6)RuCl2]2 with 7,8-benzoquinoline and 8-hydroxyquinoline

The reaction of [(C₆H₆)RuCl₂]₂ with 7,8-benzoquinoline and 8-hydroxyquinoline in methanol were performed. The obtained complexes have been studied by IR, UV–VIS, ¹H and ¹³C NMR spectroscopy and X-ray crystallography. In the reaction with 8-hydroxyquinoline the arene ruthenium(II) complex oxidized to Ru(III). The electronic spectra of the obtained compounds have been calculated using the TDDFT method. Magnetic properties of [Ru(C₉H₆NO)₃] · CH₃OH complex suggest the antiferromagnetic coupling of the ruthenium centers in the crystal lattice. EPR spectrum of [Ru(C₉H₆NO)₃] · CH₃OH compound indicates single isotropic line only characteristic for Ru³⁺ with spin equal to 1/2.     

Synthesis, structure and properties of ruthenium(II) complexes with quinolinedione derivatives as chelate ligands: Crystal structure of [Ru(CO)2Cl2(6-methoxybenzo[g]quinoline-5,10-dione)]

The reaction of the dimer complex [{Ru(CO)₃Cl₂}₂] with the ligands 4,6-dichloroquinoline-5,8-dione and 6-methoxybenzo[g]quinoline-5,10-dione in ethanol solution led to the neutral mononuclear complexes of general formula [Ru(CO)₂Cl₂(κ²-quinolinedione-N,O)]. The complexes were characterized by elemental analysis, IR and RMN spectroscopy, and the molecular structure of [Ru(CO)₂Cl₂(6-methoxybenzo[g]quinoline-5,10-dione)] was determined by single-crystal X-ray diffraction. The redox chemistry of ligands and complexes was investigated by cyclic voltammetry, and their potential antitumor activity was also evaluated.     

Reactions of transition-metal carbonyls with anhydrous HF

The reactions of a wide range of transition-metal carbonyls with anhydrous HF are described. In particular, Ru₃(CO)₁₂, Os₃(CO)₁₂ and Ir₄(CO)₁₂ give the solution stable [Ru₃(CO)₁₂H]⁺, [Ru(CO)₅H]⁺, [Os₃(CO)₁₂H]⁺, [Os(CO)₅H]⁺ and [Ir₄(CO)₁₂H₂]²⁺ respectively, which have been characterised by a combination of ¹H and ¹³C NMR spectroscopy.     

Synthese und reaktivität von dienylmetall-verbindungen : XXVII. Ein einfacher weg zur synthese von cyclopentadienylcobalt(III)-dikationen

CpCo(CO)₂ is oxidised by [Cp₂Fe]BF₄ (Cp = C₅H₅) in the presence of neutral ligands L to give the dications [CpCoL₃]²⁺ (L = SMe₂, S(n-C₄H₉)₂, PMe₃, C₅H₅N, MeCN; Me = CH₃). In [CpCo(SMe₂)₃]²⁺, sulfane ligands are substituted by neutral ligands L, L---L and L---L---L, to give the complexes [CpCoL₃]²⁺ (L = SeMe₂, TeMe₂, PMe₃, P(OMe)₃, AsMe₃, SbMe₃, t-C₄H₉NC, C₅H₅N, MeCN), [Cp-Co(L---L)SMe₂]²⁺ (L---L = R₂P(CH₂)_nPR₂, n = 1, 2, R = C₆H₅; bipyridine, o-phenanthroline, neocuproin) and [CpCo(L---L---L)]²⁺ (L---L---L = RP(CH₂CH₂PR₂)₂, R = C₆H₅). The dications react with iodide resulting in the monocations [CpCoL₂I]⁺ and [CpCo(L---L)I]⁺. Azacobaltocinium cations [CpCo(C₄R₂H₂N)]⁺ (R = H, CH₃) are obtained by reaction of [CpCo(SMe₂)₃]²⁺ with metal pyrrolides.     

Reactivity and electronic property of decaphenylmetallocenes of Mo and W atoms

The perphenylmetallocene complexes (η⁵-C₅Ph₅)₂W (1), [(η⁵-C₅Ph₅)₂W]⁺I₃⁻ (1⁺I₃), (η⁵-C₅Ph₅)₂Mo (2) and [(η⁵-C₅Ph₅)₂Mo]⁺I₃⁻ (2⁺I₃) have been prepared. Hydrogenation of 1 in THF produces (η⁵-C₅Ph₅)₂WH₂ (4), while (η⁵-C₅Ph₅)₂WHCl (3) is afforded in 1,2-dichloroethane solvent. Carbonylation of 1 produces (η⁵-C₅Ph₅)₂W(CO) (5). Treatment of 1 with the strong acid CF₃SO₃H leads to the dicationic species [(η⁵-C₅Ph₅)₂W]⁺²[CF₃SO₃]⁻₂ (1⁺²Tf₂) after crystallization. The structures of 2⁺I₃ and 1⁺²Tf₂ have been determined by an X-ray diffraction study. The magnetic susceptibility study indicates a ³E_2g ground-state for 1 and 2, and a ⁴A_2g ground-state for 1⁺ and 2⁺.     

Photodynamic action of bis(tertiary arsine (diars)) metal(III) complexes trans-[M(diars)2X2] (X = Cl, Br, I); M = Co, Cr, Rh: Optical and EPR spin-trapping studies

Photodynamic properties of series of metal complexes having the general formula [M(diars)₂X₂]ClO₄ or BF₄ where M = Co³⁺, Cr³⁺, Rh³⁺; X = Cl, Br, I, diars = o-phenylene bis(dimethylarsine) are studied. Photogeneration of singlet oxygen is monitored by both optical and EPR methods. In comparison with rose bengal ((¹O₂) for RB = 0.76), singlet oxygen generating efficiencies of these complexes are determined. Rate of N,N-dimethyl-4-nitrosoaniline (RNO) bleaching is found to be retarded by specific ¹O₂ quencher NaN₃, confirming the involvement of ¹O₂ as an active intermediate. Photolysis of these complexes in the presence of spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) generates 12-line EPR spectra, characteristic of O₂⁻ adduct. Photogeneration of O₂⁻ is also monitored by optical spectroscopy using superoxide dismutase (SOD) inhibitable cytochrome c reduction assay. The results indicate that the [Co(diars)₂Br₂]ClO₄ complex possesses high ability to generate reactive oxygen species (ROS). Both Type I and II paths are involved in the photosensitisation of the metal complexes. The antimicrobial activity of the complexes against selected bacteria is estimated. The relationship between the enzymatic production of ROS and antimicrobial activity of the complexes is examined and a good correlation between two factors is found. The [CoBr₂(diars)₂]ClO₄ complex investigated in this study effect photo cleavage of the plasmid DNA (pUC18).